飞机水上漂浮特性的数值分析

发布时间：2018-07-10 05:25

本文选题：水上迫降 + 漂浮特性　；参考：《武汉理工大学》2013年硕士论文

【摘要】：伴随着飞机跨水域飞行任务的增多,水上事故的发生不可避免,机毁人亡的事故时有发生。根据中国民用航空总局颁布的《中国民用航空规章第25部：运输类飞机适航标准》中的要求,需要对飞机水上迫降漂浮特性进行分析,以确保乘员能安全撤离飞机并乘上救生船。迫降后飞机的漂浮特性如何,是降低人员伤亡的核心问题,近年来已经成为飞机设计部门和适航认证部门研究的重点。传统的研究飞机水上迫降漂浮性能的方法主要有模型实验、经验公式以及理论模型。然而模型实验成本高、耗时长,经验和理论公式缺乏对具体问题的复杂性的反应。随着计算机的发展,采用数值方法模拟飞机水上迫降的全过程,对飞机迫降性能和漂浮性能进行评价,已经成为目前航空界的主流方法。基于上述原因本文应用显示有限元程序,采用ALE流固耦合的方法对飞机水上迫降的漂浮性能进行了研究。论文研究的目的是通过对飞机不同工况的静水漂浮做出对比分析,为飞机水上漂浮性能的设计提供准则,得到漂浮姿态、吃水深度等物理量等为飞机水上迫降的适航认证提供数据支撑。根据上述的研究目的和研究重点,论文对以下内容进行了深入细致的研究： 1.水上漂浮数值模型建立的研究,主要包括边界条件,有限元网格的建立以及流固耦合参数的选择。 2.采用显式动力学方法,引入ALE方法描述流体域,用罚函耦合算法表达了流体与固体间的耦合作用,对飞机静水漂浮的问题进行了模拟研究。 3.针对飞机漂浮问题中飞机下沉过程中的扰动问题,通过施加阻尼方式改进了此有限元算方法。研究表明通过施加阻尼可以消除飞机下沉过程中的扰动现象。 4.改变飞机重心位置对不同工况条件下飞机漂浮特性进行对比研究,分析不同工况对飞机漂浮特性的影响。研究表明前中后重心位置的改变对飞机的漂浮稳定性和吃水深度影响较小,侧向重心位置的改变对飞机吃水深度影响较小,但对飞机的稳定性有较明显影响。
[Abstract]:With the increase of aircraft missions across the water, water accidents occur inevitably, aircraft damage accidents occur from time to time. According to the requirements in the regulations on Civil Aviation of China promulgated by the General Administration of Civil Aviation of China, part 25: airworthiness Standards for Transport aircraft, it is necessary to analyze the floating characteristics of aircraft on water. To ensure that the crew can safely evacuate the aircraft and aboard the lifeboat. The floating characteristic of aircraft after forced landing is the core problem to reduce casualties. In recent years, it has become the focus of the aircraft design department and airworthiness certification department. The traditional methods to study the floating performance of aircraft forced landing on water mainly include model experiment, empirical formula and theoretical model. However, the cost of the model experiment is high, the time is long, and the experience and theoretical formula are lack of response to the complexity of the specific problem. With the development of computer, numerical method is used to simulate the whole process of aircraft landing on water, and to evaluate the performance and floating performance of aircraft forced landing has become the mainstream method in aviation field. Based on the above reasons, the floating performance of aircraft forced landing on water was studied by means of ale fluid-solid coupling method using the finite element program. The purpose of this paper is to make a comparative analysis of the aeroplane's hydrostatic floating under different working conditions, and to provide the criteria for the design of the aircraft's floating performance on water, and to obtain the floating attitude. Such physical quantities as draught depth provide data support for airworthiness certification of aircraft landing on water. According to the above research purpose and research focus, the thesis makes a thorough and detailed study on the following contents: 1. The research on the establishment of floating numerical model on water includes boundary conditions, finite element meshes and the choice of fluid-solid coupling parameters. 2. The explicit dynamics method and ale method are introduced to describe the fluid domain. The coupling between fluid and solid is expressed by the penalty function coupling algorithm. The problem of aeroplane floating in still water is simulated and studied. The finite element method is improved by applying damping to the disturbance problem of aircraft sinking in floating problem. Research shows that damping can eliminate the disturbance in the sinking process. 4. 4. The effects of different working conditions on the floating characteristics of aircraft were studied by changing the center of gravity of the aircraft. The results show that the change of the center of gravity has little effect on the floatation stability and the draught depth of the aircraft, while the change of the lateral center of gravity has little effect on the draught depth of the aircraft, but has obvious influence on the stability of the aircraft.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：V328;O35

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